CN108883286B

CN108883286B - Implantable medical device with rechargeable battery

Info

Publication number: CN108883286B
Application number: CN201780022033.8A
Authority: CN
Inventors: 基思·R·迈莱; 迈克尔·J·凯恩; 威廉姆·J·林德
Original assignee: Cardiac Pacemakers Inc
Current assignee: Cardiac Pacemakers Inc
Priority date: 2016-03-31
Filing date: 2017-03-31
Publication date: 2021-12-07
Anticipated expiration: 2037-03-31
Also published as: CN108883286A; US11116988B2; EP3436142A1; WO2017173275A1; US20170281955A1

Abstract

An implantable medical device, such as a leadless cardiac pacemaker, may include a rechargeable power source. In some cases, a system may include an implanted device that includes a receive antenna and an external transmitter that transmits radio frequency energy that may be captured by the receive antenna and then converted into electrical energy that may be used to recharge a rechargeable power source. Thus, since the rechargeable power source does not have to maintain sufficient energy storage over the expected life of the implanted device, the power source itself, and thus the implanted device, may be made smaller while still meeting the life expectancy of the device.

Description

Implantable medical device with rechargeable battery

Cross Reference to Related Applications

This application claims the benefit of U.S. provisional patent application serial No. 62/316,158, filed on 31/3/2016, the disclosure of which is incorporated herein by reference.

Technical Field

The present disclosure relates generally to implantable medical devices, and more particularly to implantable medical devices having a power source that can be wirelessly charged from a remote location.

Background

Cardiac pacemakers, such as leadless cardiac pacemakers, are used to sense and pace the heart, which is susceptible to various inappropriate heart rhythms, including but not limited to bradycardia (which is a slow heart rate) and tachycardia (which is a high heart rate). In many leadless cardiac pacemakers, due to their relatively small size, a relatively large portion of the internal space of the leadless cardiac pacemaker is consumed by the battery. Since battery life determines the potential life expectancy of a leadless cardiac pacemaker, it is desirable to maximize the battery within the limits of available space.

What is desired is an implantable medical device having a long expected service life while not requiring as much battery space, thereby allowing for significantly smaller device sizes. Smaller device sizes may make the device more easily deliverable and implantable within the body, allow the device to be implantable in smaller and more confined spaces within the body, and/or may make the device less costly to produce.

Disclosure of Invention

The present disclosure relates to implantable medical devices that provide a persistent power source within a small device housing. Although a leadless cardiac pacemaker is used as an example implantable medical device, the present disclosure may be applied to any suitable implantable medical device, including, for example: neurostimulators, diagnostic devices including those that do not deliver therapy, and/or any other suitable implantable medical device as desired.

In some cases, the present disclosure relates to implantable medical devices, such as leadless cardiac pacemakers, that include a rechargeable power source (such as a rechargeable battery, a rechargeable capacitor, or a rechargeable supercapacitor). In some cases, a system may include an implanted device that includes a receive antenna and an external transmitter that transmits radio frequency energy that may be captured by the receive antenna and then converted into electrical energy that may be used to recharge a rechargeable power source. Thus, since the rechargeable power source does not have to maintain sufficient energy storage in a single charge over the entire expected life of the implanted device, the power source itself, and thus the implanted device, may be made smaller while still meeting the life expectancy of the device.

In an example of the present disclosure, an Implantable Medical Device (IMD) configured to be implanted within a patient includes a housing configured for transcatheter deployment and a plurality of electrodes exposed outside of the housing. A therapy circuit is disposed within the housing and is operably coupled to the plurality of electrodes and configured to sense one or more signals via one or more of the plurality of electrodes and/or stimulate tissue via one or more of the plurality of electrodes. The rechargeable power source may be disposed within the housing and may be configured to power the therapy circuit. The receive antenna may be disposed relative to the housing and may be configured to receive radiated Electromagnetic (EM) energy transmitted through the patient's body. The charging circuit may be operably coupled with the receive antenna and the rechargeable power source, and may be configured to charge the rechargeable power source using radiated EM energy received via the receive antenna.

Alternatively or additionally to any of the embodiments above, the IMD may further include a secondary battery disposed within the housing and operatively coupled to the therapy circuitry, the secondary battery serving as a backup battery for the rechargeable power source.

Alternatively or additionally to any of the embodiments above, the secondary battery is a non-rechargeable battery.

Alternatively or additionally to any of the embodiments above, the IMD is a Leadless Cardiac Pacemaker (LCP).

Alternatively or additionally to any of the embodiments above, the housing is substantially transparent to the radiated EM energy.

Alternatively or additionally to any of the embodiments above, the housing may comprise a ceramic housing, a glass housing, or a polymer housing.

Alternatively or additionally to any of the embodiments above, the receive antenna may include a first metal pattern formed on an outer surface of the sleeve insert and a second metal pattern formed on an inner surface of the sleeve insert, and the sleeve insert is configured to be inserted into an elongated cavity of a housing of the IMD.

Alternatively or additionally to any of the embodiments above, the receive antenna may include a first metal pattern formed on an outer surface of the outer sleeve and a second metal pattern formed on an inner surface of the outer sleeve, and the outer sleeve is configured to fit over and be fixed relative to a housing of the IMD.

Alternatively or additionally to any of the embodiments above, at least one of the plurality of electrodes forms a portion of a receive antenna.

In another example of the present disclosure, an Implantable Medical Device (IMD) configured to be implanted within a patient includes a housing substantially transparent to radiated Electromagnetic (EM) energy along at least a portion of a length thereof and circuitry disposed within the housing. The plurality of electrodes may be exposed outside the housing and operatively coupled to the circuit. A rechargeable power source may be disposed within the housing and may be configured to power an IMD including circuitry. The receive antenna may be disposed within the housing and may be configured to receive radiated EM energy transmitted through at least a portion of the housing that is substantially transparent to the radiated EM energy. The circuit may be operably coupled with the receive antenna and the rechargeable power source and configured to charge the rechargeable power source using radiated EM energy received via the receive antenna.

Alternatively or additionally to any of the embodiments above, the IMD is an implantable monitoring device.

Alternatively or additionally to any of the embodiments above, the IMD is an implantable sensor.

Alternatively or additionally to any of the embodiments above, the receive antenna may include a first receive antenna having a first null and a second receive antenna having a second null offset from the first null.

Alternatively or additionally to any of the embodiments above, the housing may comprise a ceramic.

Alternatively or additionally to any of the embodiments above, the housing may comprise glass.

Alternatively or additionally to any of the embodiments above, the receive antenna may be configured to receive sufficient radiated EM energy from a band of radiated EM energy transmitted from outside the patient to recharge the rechargeable power source at a faster rate than the rechargeable power source is depleted by powering the IMD when the band of radiated EM energy is transmitted at an intensity that does not cause thermal damage to the patient.

Alternatively or additionally to any of the embodiments above, at least a portion of the housing has a substantially cylindrical profile and the receive antenna comprises a planar antenna that has conformed to the substantially cylindrical profile.

In another example of the present disclosure, an Implantable Medical Device (IMD) configured to be implanted within a patient includes a housing forming at least a portion of a receive antenna, wherein the receive antenna is configured to receive transmitted radiated Electromagnetic (EM) energy through the patient's body. The plurality of electrodes may be exposed outside the housing, and the circuit may be disposed within the housing. The circuit may be operably coupled to the plurality of electrodes and may be configured to sense one or more signals via one or more of the plurality of electrodes and/or may stimulate tissue via one or more of the plurality of electrodes. A rechargeable power source may be disposed within the housing and may be configured to power the circuitry. The charging circuit may be operably coupled with the receive antenna and the rechargeable power source, and may be configured to charge the rechargeable power source using radiated EM energy received via the receive antenna.

Alternatively or additionally to any of the embodiments above, the housing may form one or more layers of the receive antenna.

The above summary of some illustrative embodiments is not intended to describe each disclosed embodiment or every implementation of the present disclosure. The figures and the description that follow more particularly exemplify these and other illustrative embodiments.

Drawings

The disclosure may be more completely understood in consideration of the following description in connection with the accompanying drawings, in which:

fig. 1 is a schematic block diagram of an illustrative Leadless Cardiac Pacemaker (LCP);

FIG. 2 is a schematic block diagram of an illustrative medical device that may be used in conjunction with the LCP of FIG. 1;

fig. 3 is a schematic view of a patient including a rechargeable implantable medical device system;

fig. 4 is a schematic diagram of an illustrative Implantable Medical Device (IMD) according to an example of the present disclosure;

fig. 5 is a schematic diagram of another illustrative IMD according to an example of the present disclosure;

fig. 6 is a schematic diagram of another IMD according to an example of the present disclosure;

figure 7 is a partial cross-sectional side view of an LCP according to an example of the present disclosure;

FIG. 8 is a schematic view of an illustrative IMD with an inner sleeve insert;

FIG. 9 is a schematic view of an illustrative IMD with an outer sleeve; and is

Fig. 10-14 are schematic diagrams illustrating exemplary receive antenna configurations.

While the disclosure is amenable to various modifications and alternative forms, specifics thereof have been shown by way of example in the drawings and will be described in detail. It should be understood, however, that the intention is not to limit the disclosure to the particular embodiments described. On the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the disclosure.

Detailed Description

For the following defined terms, these definitions shall be applied, unless a different definition is given in the claims or elsewhere in this specification.

All numerical values are herein assumed to be modified by the term "about", whether or not explicitly indicated. The term "about" generally refers to a range of numbers that one of skill in the art would consider equivalent to the recited value (i.e., having the same function or result). In many cases, the term "about" may include numbers that are rounded to the nearest significant figure.

The recitation of numerical ranges by endpoints includes all numbers subsumed within that range (e.g. 1 to 5 includes 1, 1.5, 2, 2.75, 3, 3.80, 4, and 5).

As used in this specification and the appended claims, the singular forms "a", "an", and "the" include plural referents unless the content clearly dictates otherwise. As used in this specification and the appended claims, the term "or" is generally employed in its sense (including "and/or") unless the content clearly dictates otherwise.

It should be noted that references in this specification to "an embodiment," "some embodiments," "other embodiments," etc., indicate that the embodiment described may include one or more particular features, structures, and/or characteristics. However, such recitation does not necessarily imply that all embodiments include the particular features, structures, and/or characteristics. Further, when a particular feature, structure, and/or characteristic is described in connection with an embodiment, it is understood that unless explicitly stated to the contrary, such feature, structure, and/or characteristic may be used in connection with other embodiments whether or not explicitly described.

The following description should be read with reference to the drawings, in which like structures in different drawings are identically numbered. The drawings, which are not necessarily to scale, depict illustrative embodiments and are not intended to limit the scope of the disclosure.

Fig. 1 is a conceptual schematic block diagram of an illustrative Leadless Cardiac Pacemaker (LCP) that may be implanted on or within a heart or ventricle of a patient and that may operate to sense physiological signals and parameters and deliver one or more types of electrical stimulation therapy to the patient's heart. Exemplary electrical stimulation therapies may include bradycardia pacing, frequency response pacing therapy, Cardiac Resynchronization Therapy (CRT), and/or anti-tachycardia pacing (ATP) therapy, among others. As can be seen in fig. 1, LCP100 may be a compact device having all of the components housed within LCP100 or directly on housing 120. In some cases, LCP100 may include one or more of a communication module 102, a pulse generator module 104, an electrical sensing module 106, a mechanical sensing module 108, a processing module 110, an energy storage module 112, and electrodes 114.

As depicted in fig. 1, LCP100 may include electrodes 114, which may be fixed relative to housing 120 and electrically exposed to tissue and/or blood surrounding LCP 100. Electrodes 114 may generally conduct electrical signals to and from LCP100 and surrounding tissue and/or blood. Such electrical signals may include, for example, communication signals, electrical stimulation pulses, and intrinsic cardiac electrical signals. The intrinsic cardiac electrical signal may comprise an electrical signal generated by the heart and may be represented by an Electrocardiogram (ECG).

The electrodes 114 may comprise one or more biocompatible conductive materials, such as various metals or alloys known to be safely implantable in the human body. In some cases, electrodes 114 may be disposed generally on either end of LCP100 and may be in electrical communication with one or more of

modules

102, 104, 106, 108, and 110. In embodiments in which electrodes 114 are directly secured to housing 120, an insulating material may electrically isolate electrodes 114 from adjacent electrodes, housing 120, and/or other portions of LCP 100. In some cases, some or all of electrodes 114 may be spaced apart from housing 120 and connected to housing 120 and/or other components of LCP100 by connecting wires. In such a case, the electrodes 114 may be placed on a tail (not shown) extending away from the housing 120. As shown in fig. 1, in some embodiments, LCP100 may include electrodes 114'. The electrodes 114' may be in addition to the electrodes 114, or may replace one or more of the electrodes 114. Electrodes 114 'may be similar to electrodes 114, except that electrodes 114' are disposed on the sides of LCP 100. In some cases, electrodes 114' may increase the number of electrodes through which LCP100 may deliver communication signals and/or electrical stimulation pulses, and/or sense intrinsic cardiac electrical signals, communication signals, and/or electrical stimulation pulses.

Electrodes 114 and/or 114' may take any of a variety of sizes and/or shapes and may be spaced at any of a variety of intervals. For example, the electrode 114 may have an outer diameter of two to twenty millimeters (mm). In other embodiments, the electrodes 114 and/or 114' may have a diameter of two, three, five, seven millimeters (mm) or any other suitable diameter, size, and/or shape. Example lengths of electrodes 114 and/or 114' may include, for example, lengths of one, three, five, ten millimeters (mm), or any other suitable length. As used herein, the length is the dimension of the electrode 114 and/or 114' that extends away from the outer surface of the housing 120. In some cases, at least some of the electrodes 114 and/or 114' may be spaced apart from each other by a distance of twenty, thirty, forty, fifty millimeters (mm), or any other suitable spacing. The electrodes 114 and/or 114' of a single device may have different dimensions relative to one another, and the spacing and/or length of the electrodes on the device may or may not be uniform.

In the illustrated embodiment, the communication module 102 may be electrically coupled to the electrodes 114 and/or 114 'and may be configured to deliver communication pulses to the patient's tissue to communicate with other devices, such as sensors, programmers, and/or other medical devices. As used herein, a communication signal may be any modulated signal that conveys information to another device, either by itself or in combination with one or more other modulated signals. In some embodiments, the communication signal may be limited to a sub-threshold signal that does not result in cardiac capture but still conveys information. The communication signal may be delivered to another device located outside or inside the patient's body. In some cases, the communication may take the form of different communication pulses separated by various amounts of time. In some of these cases, the timing between successive pulses may convey information. The communication module 102 may additionally be configured to sense communication signals delivered by other devices that may be located outside or inside the patient's body.

The communication module 102 may communicate to help perform one or more desired functions. Some example functions include delivering sensed data, using the transmitted data to determine the occurrence of an event such as an arrhythmia, coordinating the delivery of electrical stimulation therapy, and/or other functions. In some cases, LCP100 may use communication signals to communicate raw information, processed information, messages and/or commands, and/or other data. The raw information may include information such as sensed electrical signals (e.g., sensed ECG) and signals collected from coupled sensors. In some embodiments, the processed information may include signals that have been filtered using one or more signal processing techniques. The processed information may also include parameters and/or events determined by LCP100 and/or other devices, such as a determined heart rate, a timing of a determined heartbeat, a timing of other determined events, a determination of a threshold crossing point, expiration of a monitored time period, accelerometer signals, activity level parameters, blood oxygen parameters, blood pressure parameters, and heart sound parameters, among others. In some cases, the processed information may be provided, for example, by a chemical sensor or an optical interface sensor (optical interface sensor). The message and/or command may include an instruction or the like directing another device to take an action, a notification of an impending action by the sending device, a request to read from the receiving device, a request to write data to the receiving device, an information message, and/or other message commands.

In at least some embodiments, communication module 102 (or LCP 100) may also include switching circuitry to selectively connect one or more of electrodes 114 and/or 114 'to communication module 102 in order to select which of electrodes 114 and/or 114' communication module 102 delivers a communication pulse. It is contemplated that the communication module 102 may communicate with other devices via conducted signals, Radio Frequency (RF) signals, optical signals, acoustic signals, inductive coupling, and/or any other suitable communication methodology. In the case where the communication module 102 produces an electrical communication signal, the communication module 102 may include one or more capacitor elements and/or other charge storage devices to assist in generating and delivering the communication signal. In the illustrated embodiment, the communication module 102 may use the energy stored in the energy storage module 112 to generate communication signals. In at least some examples, communication module 102 may include switching circuitry connected to energy storage module 112, and energy storage module 112 may be connected to one or more of electrodes 114/114' with the switching circuitry to generate the communication signal.

As shown in fig. 1, the pulse generator module 104 may also be electrically connected to one or more of the electrodes 114 and/or 114'. Pulse generator module 104 may be configured to generate and deliver electrical stimulation pulses to tissue of the patient via one or more of electrodes 114 and/or 114' in order to effect one or more electrical stimulation therapies. Electrical stimulation pulses as used herein are intended to include any electrical signal that may be delivered to patient tissue for the purpose of treating any type of disease or abnormality. For example, when used to treat a cardiac disorder, the pulse generator module 104 may generate electrical stimulation pacing pulses for capturing the patient's heart, i.e., causing the heart to contract in response to the delivered electrical stimulation pulses. In some of these cases, LCP100 may change the frequency at which pulse generator module 104 generates electrical stimulation pulses, such as in frequency-adaptive pacing. In other embodiments, the electrical stimulation pulses may include defibrillation/cardioversion pulses for shaking the heart out of fibrillation or into a normal heart rhythm. In still other embodiments, the electrical stimulation pulses may include anti-tachycardia pacing (ATP) pulses. It should be understood that these are only examples. When used to treat other diseases, the pulse generator module 104 may generate electrical stimulation pulses suitable for neurostimulation therapy and the like. The pulse generator module 104 may include one or more capacitor elements and/or other charge storage devices to help generate and deliver the appropriate electrical stimulation pulses. In at least some embodiments, pulse generator module 104 may generate electrical stimulation pulses using energy stored in energy storage module 112. In some particular embodiments, pulse generator module 104 may include switching circuitry that is connected to energy storage module 112, and may connect energy storage module 112 to one or more of electrodes 114/114' to generate electrical stimulation pulses.

LCP100 may also include an electrical sensing module 106 and a mechanical sensing module 108. Electrical sensing module 106 may be configured to sense intrinsic cardiac electrical signals conducted from electrodes 114 and/or 114' to electrical sensing module 106. For example, electrical sensing module 106 may be electrically connected to one or more of electrodes 114 and/or 114', and electrical sensing module 106 may be configured to receive cardiac electrical signals conducted through electrodes 114 and/or 114' via a sensor amplifier or the like. In some embodiments, the cardiac electrical signals may represent local information from the chamber in which LCP100 is implanted. For example, if LCP100 is implanted within a ventricle of the heart, the cardiac electrical signals sensed by LCP100 through electrodes 114 and/or 114' may represent ventricular cardiac electrical signals. Mechanical sensing module 108 may include or be electrically connected to various sensors, such as accelerometers (including multi-axis accelerometers such as two-axis or three-axis accelerometers), gyroscopes (including multi-axis gyroscopes such as two-axis or three-axis gyroscopes), blood pressure sensors, heart sound sensors, piezoelectric sensors, blood oxygen sensors, and/or other sensors that measure one or more physiological parameters of the heart and/or patient. Mechanical sensing module 108 (when present) may collect signals from sensors indicative of various physiological parameters. Both the electrical sensing module 106 and the mechanical sensing module 108 may be connected to the processing module 110 and may provide signals representative of the sensed cardiac and/or physiological signals to the processing module 110. Although described with respect to fig. 1 as separate sensing modules, in some embodiments, electrical sensing module 106 and mechanical sensing module 108 may be combined into a single module. In at least some examples, LCP100 may include only one of electrical sensing module 106 and mechanical sensing module 108. In some cases, any combination of processing module 110, electrical sensing module 106, mechanical sensing module 108, communication module 102, pulse generator module 104, and/or energy storage module may be considered a controller of LCP 100.

Processing module 110 may be configured to direct the operation of LCP100 and may be referred to as a controller in some embodiments. For example, processing module 110 may be configured to receive cardiac electrical signals from electrical sensing module 106 and/or physiological signals from mechanical sensing module 108. Based on the received signals, processing module 110 may determine, for example, the occurrence and type of arrhythmia, as well as other determinations such as whether LCP100 has been dislocated (dislogge). The processing module 110 may also receive information from the communication module 102. In some embodiments, processing module 110 may additionally use such received information to determine the occurrence and type of arrhythmia, and/or other determinations such as whether LCP100 has been dislocated. In yet additional embodiments, LCP100 may use the received information instead of the signals received from electrical sensing module 106 and/or mechanical sensing module 108-e.g., if the received information is deemed more accurate than the signals received from electrical sensing module 106 and/or mechanical sensing module 108, or if electrical sensing module 106 and/or mechanical sensing module 108 have been disabled or omitted from LCP 100.

After determining that an arrhythmia is occurring, processing module 110 may control pulse generator module 104 to generate electrical stimulation pulses according to one or more electrical stimulation therapies to treat the determined arrhythmia. For example, processing module 110 may control pulse generator module 104 to generate pacing pulses with varying parameters and in different sequences to implement one or more electrical stimulation therapies. As one example, in controlling pulse generator module 104 to deliver bradycardia pacing therapy, processing module 110 may control pulse generator module 104 to deliver pacing pulses designed to capture the patient's heart at regular intervals to help prevent the patient's heart from falling below a predetermined threshold. In some cases, the pacing rate may increase as the level of patient activity increases (e.g., frequency adaptive pacing). For example, the processing module 110 may monitor one or more physiological parameters of the patient that may indicate a need for an increased heart rate (e.g., due to increased metabolic demand). Processing module 110 may then increase the frequency at which pulse generator module 104 generates electrical stimulation pulses. Adjusting the delivery frequency of electrical stimulation pulses based on one or more physiological parameters may extend the battery life of LCP100 by requiring a higher delivery frequency of electrical stimulation pulses only when the physiological parameters indicate a need for increased cardiac output. Furthermore, adjusting the delivery frequency of the electrical stimulation pulses may increase the comfort level of the patient by more closely matching the delivery frequency of the electrical stimulation pulses to the cardiac output requirements of the patient.

For ATP therapy, the processing module 110 may control the pulse generator module 104 to deliver pacing pulses at a faster rate than the patient's intrinsic heart rate in an attempt to force the heart to beat in response to the delivered pacing pulses rather than in response to the intrinsic cardiac electrical signal. Once the heart is following the pacing pulses, processing module 110 may control pulse generator module 104 to reduce the frequency of the delivered pacing pulses to a safer level. In CRT, the processing module 110 may control the pulse generator module 104 to deliver pacing pulses in coordination with another device to cause the heart to contract more efficiently. In the case where pulse generator module 104 is capable of generating defibrillation and/or cardioversion pulses for defibrillation/cardioversion therapy, processing module 110 may control pulse generator module 104 to generate such defibrillation and/or cardioversion pulses. In some cases, processing module 110 may control pulse generator module 104 to generate electrical stimulation pulses to provide electrical stimulation therapies other than those examples described above.

In addition to controlling pulse generator module 104 to generate electrical stimulation pulses of different types and in different sequences, in some embodiments, processing module 110 may also control pulse generator module 104 to generate various electrical stimulation pulses with varying pulse parameters. For example, each electrical stimulation pulse may have a pulse width and a pulse amplitude. Processing module 110 may control pulse generator module 104 to generate various electrical stimulation pulses having particular pulse widths and pulse amplitudes. For example, if the electrical stimulation pulses do not effectively capture the heart, processing module 110 may cause pulse generator module 104 to adjust the pulse width and/or pulse amplitude of the electrical stimulation pulses. Such control of particular parameters of various electrical stimulation pulses may help LCP100 provide more efficient delivery of electrical stimulation therapy.

In some embodiments, the processing module 110 may also control the communication module 102 to send information to other devices. For example, the processing module 110 may control the communication module 102 to generate one or more communication signals for communicating with other devices of the system of devices. For example, the processing module 110 may control the communication module 102 to generate communication signals in a particular sequence of pulses, where the particular sequence conveys different information. The communication module 102 may also receive communication signals for potential action by the processing module 110.

In further embodiments, the processing module 110 may control the switching circuitry through which the communication module 102 and the pulse generator module 104 deliver the communication signals and/or electrical stimulation pulses to the tissue of the patient. As described above, both the communication module 102 and the pulse generator module 104 may include circuitry for connecting one or more of the electrodes 114 and/or 114' to the communication module 102 and/or the pulse generator module 104 so these modules may deliver communication signals and electrical stimulation pulses to the tissue of the patient. The particular combination of one or more electrodes through which communication module 102 and/or pulse generator module 104 deliver the communication signal and the electrical stimulation pulse may affect the reception of the communication signal and/or the effectiveness of the electrical stimulation pulse. Although it is described that each of the communication module 102 and the pulse generator module 104 may include switching circuitry, in some embodiments, the LCP100 may have a single switching module connected to the communication module 102, the pulse generator module 104, and the electrodes 114 and/or 114'. In such embodiments, processing module 110 may control the switching module to connect module 102/104 and electrode 114/114' as appropriate.

In some embodiments, processing module 110 may comprise a preprogrammed chip, such as a Very Large Scale Integration (VLSI) chip or an Application Specific Integrated Circuit (ASIC). In such embodiments, the chip may be pre-programmed with control logic to control the operation of LCP 100. By using a pre-programmed chip, processing module 110 may use less power than other programmable circuitry while being able to maintain basic functionality, thereby potentially increasing the battery life of LCP 100. In other cases, the processing module 110 may include a programmable microprocessor or the like. Such a programmable microprocessor may allow a user to adjust the control logic of LCP100 after manufacture, allowing LCP100 greater flexibility than when using a preprogrammed chip. In still other embodiments, the processing module 110 may not be a single component. For example, processing module 110 may include multiple components positioned at different locations within LCP100 to perform various described functions. For example, some functions may be performed in one component of the processing module 110 while other functions are performed in a separate component of the processing module 110.

In further embodiments, the processing module 110 may include memory circuitry, and the processing module 110 may store information on and read information from the memory circuitry. In other embodiments, LCP100 may include separate memory circuitry (not shown) in communication with processing module 110 such that processing module 110 may read information from and write information to the separate memory circuitry. The memory circuitry (whether part of the processing module 110 or separate from the processing module 110) may be volatile memory, non-volatile memory, or a combination of volatile and non-volatile memory.

Energy storage module 112 may provide power to LCP100 for its operation. In some embodiments, the energy storage module 112 may be a non-rechargeable lithium-based battery. In other embodiments, the non-rechargeable battery may be made of other suitable materials. In some embodiments, energy storage module 112 may be considered a rechargeable power source, such as, but not limited to, a rechargeable battery. In still other embodiments, the energy storage module 112 may include other types of energy storage devices, such as capacitors or supercapacitors. In some cases, as will be discussed, energy storage module 112 may include a rechargeable primary battery and a non-rechargeable secondary battery. In some cases, both the primary and secondary batteries, if present, may be rechargeable.

To implant LCP100 within a patient, an operator (e.g., a physician, clinician, etc.) may secure LCP100 to cardiac tissue of the patient's heart. To facilitate fixation, LCP100 may include one or more anchors (anchors) 116. The one or more anchors 116 are schematically shown in fig. 1. The one or more anchors 116 may include any number of securing or anchoring mechanisms. For example, one or more anchors 116 can include one or more pins, staples, threads, screws, and/or tines, among others. In some embodiments, although not shown, one or more anchors 116 can include threads on an outer surface thereof that can travel along at least a portion of the length of the anchor member. The threads may provide friction between the heart tissue and the anchor to help secure the anchor member within the heart tissue. In some cases, one or more anchors 116 may comprise an anchor member having a corkscrew-screw shape that may be screwed into cardiac tissue. In other embodiments, the anchor 116 may include other structures, such as barbs, spikes, and the like, to facilitate engagement with the surrounding cardiac tissue.

In some examples, LCP100 may be configured to be implanted on or within a chamber of a patient's heart. For example, LCP100 may be implanted within any one of the left atrium, right atrium, left ventricle, or right ventricle of a patient's heart. By being implanted within a particular chamber, LCP100 may be able to sense cardiac electrical signals emanating from or coming out of a particular chamber, while other devices may not be able to sense at such resolution. Where LCP100 is configured to be implanted on a patient's heart, LCP100 may be configured to be implanted on or near one chamber of the heart, or on or near a path that is typically followed along inherently generated cardiac electrical signals. In these examples, LCP100 may also have enhanced capabilities to sense local intrinsic cardiac electrical signals and deliver local electrical stimulation therapy. In embodiments where LCP100 includes an accelerometer, LCP100 may additionally be capable of sensing motion of the heart wall to which LCP100 is attached.

Although a leadless cardiac pacemaker is used in fig. 1 as an example implantable medical device, the present disclosure may be applied to any suitable implantable medical device, including, for example: neurostimulators, diagnostic devices including those that do not deliver therapy, and/or any other suitable implantable medical device as desired.

Fig. 2 is a schematic block diagram of an illustrative Medical Device (MD)200 that may be used with LCP100 of fig. 1. In some cases, MD200 may be configured to sense physiological signals and parameters and deliver one or more types of electrical stimulation therapy to a patient's tissue. In the illustrated embodiment, MD200 may include a communication module 202, a pulse generator module 204, an electrical sensing module 206, a mechanical sensing module 208, a processing module 210, and an energy storage module 218. Each of

modules

202, 204, 206, 208, and 210 may be similar to

modules

102, 104, 106, 108, and 110 of LCP 100. Furthermore, energy storage module 218 may be similar to energy storage module 112 of LCP 100. However, in some embodiments, MD200 may have a larger volume within housing 220. In such embodiments, MD200 may include a larger energy storage module 218 and/or a larger processing module 210 capable of handling more complex operations than processing module 110 of LCP 100.

While MD200 may be another leadless device such as that shown in fig. 1, in some cases MD200 may include leads such as lead 212. In some cases, lead 212 may include wires that conduct electrical signals between electrode 214 and one or more modules located within housing 220. In some cases, the leads 212 may be connected to the housing 220 of the MD200 and extend away from the housing 220. In some embodiments, the lead 212 is implanted on, within, or adjacent to the patient's heart. Lead 212 may include one or more electrodes 214 positioned at various locations on lead 212 and at various distances from housing 220. Some leads 212 may include only a single electrode 214, while other leads 212 may include multiple electrodes 214. Typically, the electrodes 214 are positioned on the lead 212 such that when the lead 212 is implanted in the patient, one or more of the electrodes 214 are positioned to perform a desired function. In some cases, one or more electrodes 214 may be in contact with cardiac tissue of the patient. In other cases, one or more electrodes 214 may be positioned subcutaneously but adjacent to the patient's heart. The electrodes 214 may conduct inherently generated cardiac electrical signals to the lead 212. The lead 212 may then conduct the received cardiac electrical signals to one or more of the

modules

202, 204, 206, and 208 of the MD 200. In some cases, MD200 may generate electrical stimulation signals, and leads 212 may conduct the generated electrical stimulation signals to electrodes 214. The electrodes 214 may then conduct electrical stimulation signals to the patient's cardiac tissue (directly or indirectly). The MD200 may also include one or more electrodes 214 not disposed on the leads 212. For example, one or more electrodes 214 may be directly connected to the housing 220.

In some embodiments, lead 212 may additionally include one or more sensors, such as an accelerometer, a blood pressure sensor, a heart sound sensor, a blood oxygen sensor, and/or other sensors configured to measure one or more physiological parameters of the heart and/or patient. In such embodiments, the mechanical sensing module 208 may be in electrical communication with the leads 212 and may receive signals generated from such sensors. In some cases, one or more of these additional sensors may instead be incorporated into or on MD 200.

Although not required, in some embodiments, MD200 may be an implantable medical device. In such embodiments, housing 220 of MD200 may be implanted, for example, in a transthoracic region of a patient. Housing 220 may generally comprise any of a variety of known materials that are safe for implantation in the human body, and may hermetically seal the various components of MD200 from fluids and tissues of the patient's body when implanted. In such embodiments, the lead 212 may be implanted at one or more different locations within the patient's body, such as within the patient's heart, adjacent the patient's spine, or any other desired location.

In some embodiments, MD200 may be an Implantable Cardiac Pacemaker (ICP). In these embodiments, MD200 may have one or more leads, such as lead 212, implanted on or within the patient's heart. One or more leads 212 may include one or more electrodes 214 in contact with cardiac tissue and/or blood of the patient's heart. MD200 may be configured to sense inherently generated cardiac electrical signals and determine, for example, one or more arrhythmias based on analysis of the sensed signals. MD200 may be configured to deliver CRT, ATP therapy, bradycardia therapy, and/or other types of therapy via leads 212 implanted within the heart. In some embodiments, MD200 may additionally be configured to provide defibrillation/cardioversion therapy.

In some cases, MD200 may be an Implantable Cardioverter Defibrillator (ICD). In such embodiments, MD200 may include one or more leads implanted within a patient's heart. MD200 may also be configured to sense cardiac electrical signals, determine an occurrence of a tachyarrhythmia based on the sensed cardiac electrical signals, and deliver defibrillation and/or cardioversion therapy (e.g., by delivering defibrillation and/or cardioversion pulses to a heart of a patient) in response to determining the occurrence of the tachyarrhythmia. In other embodiments, MD200 may be a Subcutaneous Implantable Cardioverter Defibrillator (SICD). In embodiments where MD200 is an SICD, one of leads 212 may be a subcutaneously implanted lead. In at least some embodiments in which MD200 is an SICD, MD200 may include only a single lead implanted subcutaneously but outside the thorax, however this is not required. In some cases, the lead may be implanted just below the chest cavity.

In some embodiments, MD200 may not be an implantable medical device. Rather, MD200 may be a device external to the patient's body, and electrode 214 may be a skin electrode placed on the patient's body. In such embodiments, MD200 may be capable of sensing surface electrical signals (e.g., cardiac electrical signals generated by the heart or electrical signals generated by a device implanted within the patient and conducted through the body to the skin). MD200 may also be configured to deliver various types of electrical stimulation therapy, including, for example, defibrillation therapy via skin electrodes 214.

In some cases, an implantable medical device, such as IMD 100 and/or MD200, uses a majority of its internal volume for energy storage. It will be appreciated that the expected lifetime of an implanted device is largely dependent on the expected lifetime of the battery powering the implanted device. Therefore, there is competitive interest in the desire to maximize battery life (and thus device life expectancy) while making implant devices as small as possible for delivery using various techniques, such as transcatheter delivery, and to make implant devices less invasive. In some cases, such as for implanted devices intended to be implanted in a particular chamber of the heart, there are additional potential size limitations. Devices with too large a diameter may be difficult to deliver, while devices that are too long may interfere with the operation of the valve (e.g., interfere with the valve, interfere with blood flow, etc.).

Accordingly, some implanted devices, such as, but not limited to, Leadless Cardiac Pacemakers (LCPs), may be configured to include a rechargeable battery that provides the power required by the LCP for a limited period of time. Since the rechargeable battery can be charged in situ, the rechargeable battery can be smaller because it does not have to store enough energy to last the entire expected life of the device. Instead, the rechargeable battery only needs to store enough energy to power the LCP for a period of time that corresponds to a reasonable charging schedule. For example, LCPs with rechargeable batteries may be charged daily, weekly, monthly, by-year, annually, or on any desired schedule, recognizing that the relative size of the rechargeable batteries is at least approximately proportional to the interval between recharges. For example, a relatively small rechargeable battery would take up less space within the LCP, but would require more frequent recharging. A relatively large rechargeable battery will take up more space within the LCP, but since a larger rechargeable battery can store relatively more chemical energy, less frequent recharging is required. In some cases, the battery size may be approximately inversely proportional to the frequency of impact energy (impact energy) captured and used to recharge the rechargeable battery.

In some cases, an implant device with a rechargeable battery may be implanted in a patient. In the case of an LCP with a rechargeable battery, the LCP may be implanted within a chamber of a patient's heart. The patient may periodically undergo a recharging process, wherein energy from outside the patient may be transmitted to the LCP (or other implanted device) within the patient's body. In some cases, the LCP or other implanted device may include an antenna or other structure configured to receive the transmitted energy, and the received energy may be used to at least partially recharge the rechargeable battery. It is to be understood that at least partially recharging the rechargeable battery may for example mean recharging the rechargeable battery to capacity. This may mean recharging the rechargeable battery to a charge level below capacity. For example, recharging a rechargeable battery may mean recharging to a charge level of about 50% capacity, about 60% capacity, about 70% capacity, about 80% capacity, or about 90% capacity.

Fig. 3 provides a highly schematic illustration of a patient 300, the patient 300 having an implantable device 302 implanted within the patient 300. Although the implantable device 302 is shown in or near the patient's chest, it should be understood that this is merely illustrative as the implantable device 302 can be implanted in other locations within the patient 300 depending on its function. The transmitter 304 is shown external to the patient 300. In some cases, the emitter 304 may be configured to emit Electromagnetic (EM) radiation energy having a wavelength (or frequency, as the wavelength and frequency are related to the numerical speed of the passing light) and intensity that may be safely passed into the patient 300 to the implantable device 302 without causing excessive tissue heating or other potentially damaging effects to the patient 300.

The transmitter 304 may take any of a variety of forms. For example, although shown schematically as a box in fig. 3, the transmitter 304 may be sized and configured to cause the patient 300 to periodically wear a lanyard around their neck, which will place the transmitter 304 near their chest in approximately the same vertical and horizontal position as the implantable device 302 within the patient's chest. In some cases, for example, the transmitter 304 may be built into the back of a chair in which the patient 300 will periodically sit to recharge the implantable device 302. The chair may be in the patient's home, for example, for daily charging, or may be at a remote location, such as a medical clinic, for a patient 300 with a longer charging schedule. As another example, the transmitter 304 may be built into a bed such that the transmitter 304 may at least partially recharge the implantable device 302 every night while the patient 300 is sleeping. In some cases, the transmitter 304 may be configured to transmit once per week, or once per month, for example, depending on the power requirements of the implantable device 302. In some cases, the transmitter 304 and the implantable device 302 may communicate with each other. When so set, the implantable device 302 can report its current battery recharge level to the transmitter 304, and if the current battery recharge level is below a threshold, the transmitter 304 can send power to the implantable device 302.

It should be understood that the implantable device 302 may be configured to periodically receive EM energy of a wavelength and intensity that is safe for the patient 300, and that the implantable device 302 may be used to recharge a rechargeable battery within the implantable device 302. EM energy may be received at a rate that exceeds the rate at which power is drawn from the rechargeable battery and consumed by various components within the implantable device 302.

Fig. 4 provides an illustrative, but non-limiting example of at least some of the internal components within the implantable device 302. In some cases, the implantable device 302 includes a device housing 306. In some cases, the device housing 306 may include at least a portion thereof formed of a material that is transparent, or at least substantially transparent, to EM energy transmitted from the transmitter 304 to the implantable device 302. Herein, "substantially" transparent may be defined, for example, to allow at least 70%, or at least 80%, at least 90%, or at least 95% of incident energy at a particular wavelength (or range of wavelengths) to pass through the material without being absorbed by or blocked by the material. For example, at least a portion of the device housing 306, or even all of the device housing 306, may be made of a material such as glass or ceramic. To illustrate, the first portion 306a of the device housing 306 that may cover the receive antenna 308 may be made of a material that is transparent, or at least substantially transparent, to EM energy transmitted from the transmitter 304, while the second portion 306b of the device housing 306 that does not cover the receive antenna 308 may be made of other materials, such as, but not limited to, metal, that may otherwise interfere with the transmission of EM energy from the transmitter 304 to the receive antenna 308. In some cases, both the first portion 306a and the second portion 306b may be made of a material that is transparent, or at least substantially transparent, to EM energy transmitted from the emitter 304.

Receive antenna 308 may be any of a variety of different types of antennas. In some cases, receive antenna 308 may be a planar antenna, which in some cases conforms to a non-planar surface. In some cases, the planar antenna may be an antenna printed or deposited on a flat surface, or possibly an antenna etched into a flat surface. In some cases, depending on how the receive antenna 308 is incorporated into the implantable device 302, the receive antenna 308 may be considered a three-dimensional simulation of a planar antenna (e.g., conforming to a non-planar shape). Illustrative, but non-limiting examples of planar antennas include path antennas (path antennas), slot antennas (slot antennas), loop antennas, helical antennas, bowtie antennas, tsa (vivaldi) antennas, LPDA antennas, leaky wave antennas, and quasi-yagi antennas. In some cases, the antenna may include a resonator structure that helps make the antenna more efficient and/or increases the effective electrical length of the antenna so that the antenna may be physically smaller.

EM energy transmitted from transmitter 304 may be captured by receive antenna 308 and provided to circuitry 310. In some cases, the circuitry 310 may be configured to convert the received EM energy into a form that may be used to recharge the rechargeable battery 312. In some cases, the circuitry 310 may also provide other functionality to the implantable device 302. For example, if the implantable device 302 is an LCP, the circuitry 310 may provide sensing, pacing, or both sensing and pacing functions in addition to recharging the rechargeable battery 312. In some cases, the circuitry 310 is used only to recharge the rechargeable battery 312, and the implantable device 302 may include other circuitry (not shown) to provide any other functionality attributed to the implantable device 302.

When considering the electromagnetic area around the transmitting antenna, there are three categories; namely, (1) a reactive near field; (2) a radiating near field and (3) a radiating far field. An "inductive" charging system operates in the reactive near field region. In inductive power systems, power is typically transmitted over short distances by using inductively coupled magnetic fields between coils or by using capacitively coupled electric fields between electrodes. In a radiated power system (e.g., radiating a near field and radiating a far field), power is typically transmitted by a beam of Electromagnetic (EM) energy. Radiated power systems can typically transmit energy over longer distances, but the ability of the receive antenna to capture sufficient energy can be challenging, particularly for applications where the receive antenna size is limited.

In some cases, the transmitter 304 and the implantable medical device 302 may operate at a frequency of about 400MHz or higher within the patient. When so configured, the system does not operate in the reactive near-field (as in an inductive charging system), but rather operates in the radiating near-field or far-field region (depending on the placement and band of use of the implanted device). For example, when EM energy is transmitted at 400MHz, the system is in the radiated near field region, and when EM energy is transmitted at 2.45GHz, the system is in the radiated far field region. In some cases, the present system may operate at a frequency between, for example, approximately 400MHz and 3 GHz. In some cases, more than one frequency within the range may be used simultaneously and/or sequentially. In some cases, multiple implanted devices may be charged simultaneously or sequentially using both the radiating near-field and the radiating far-field regions.

The rechargeable battery 312 may be any type of rechargeable battery 312 and may take on a three-dimensional shape that facilitates incorporation of the rechargeable battery 312 into the device housing 304. In some cases, the rechargeable battery 312 may instead be a supercapacitor. As will be appreciated, in some cases, the device housing 304 may have a cylindrical or substantially cylindrical shape, in which case a rechargeable battery 312 having a cylindrical or annular profile, such as a button battery or a (highly) elongated battery having a substantially cylindrical shape, may be useful. It should be recognized that there may be a tradeoff in shape and size of the rechargeable battery with respect to performance, and therefore these issues should be considered when designing the rechargeable battery 312 for a particular application. Although fig. 4 schematically illustrates a single rechargeable battery 312, in some cases, there may be two, three, or more different rechargeable batteries 312, each rechargeable battery 312 electrically coupled with the circuit 310. For example, in some cases, there may be a performance advantage to having multiple rechargeable batteries 312. In some cases, having multiple (and smaller) rechargeable batteries 312 may have packaging advantages.

Fig. 5 provides a schematic illustration of an IMD320, which IMD320 may be configured to be implanted within a patient, such as patient 300 (fig. 3). The illustrative IMD320 includes a housing 322, the housing 322 being substantially transparent to EM energy (such as radiated EM energy along at least a portion of its length). For example, in some cases, first portion 322a of enclosure 322 may be substantially transparent to radiant EM energy, while second portion 322b of enclosure 320 may be less transparent to radiant EM energy. In some cases, second portion 322b of housing 320 may also be substantially transparent to radiated EM energy. In some cases, at least the first portion 322a of the housing 320 may be ceramic or glass. The circuit 310 may be disposed within the housing 320. In some cases, as described with respect to fig. 4, circuit 310 may be monofunctional, meaning that its sole function is for recharging, or circuit 310 may be multifunctional, meaning that circuit 310 has additional functionality beyond recharging.

In some cases, the first electrode 324 and the second electrode 326 may be exposed outside of the housing 320 and may be operably coupled to the circuit 310. Although two electrodes are shown, it is understood that IMD320 may include three, four, or more different electrodes in some cases. Depending on the intended function of IMD320, first electrode 324 and second electrode 326 may be used in combination to sense and/or pace the patient's heart. In some cases, IMD320 may be a Leadless Cardiac Pacemaker (LCP), an implantable monitoring device, or an implantable sensor, for example. In some cases, first electrode 324 and second electrode 326 may be used in combination to communicate with other implanted devices and/or with external devices. In some cases, the communication with other implanted devices may include conductive communication, but this is not required. Rechargeable battery 312 may be disposed within housing 320 and may be configured to power IMD320 including circuitry 310.

Receive antenna 308 may be disposed within enclosure 320 and may be configured to receive radiated EM energy transmitted through enclosure 320 (such as through a first portion 322a of enclosure 320 that is substantially transparent to the radiated EM energy). The circuit 310 may be operably coupled with the receive antenna 308 and the rechargeable battery 312. In some cases, the circuit 310 may be configured to charge the rechargeable battery 312 using radiated EM energy received by the receive antenna 308. In some cases, receive antenna 308 may be configured to receive sufficient radiated EM energy from a band of radiated EM energy transmitted from outside patient 300 (fig. 3) to recharge rechargeable battery 312 at a faster rate than rechargeable battery 312 is depleted by powering IMD320 when the band of radiated EM energy is transmitted at an intensity that does not cause thermal damage to patient 300. In some cases, the housing 320 has a substantially cylindrical profile, and the receive antenna 308 comprises a planar antenna that has conformed to the substantially cylindrical profile of the inner surface of the internal cavity defined by the housing 320.

Fig. 6 provides a schematic illustration of an IMD 340, which IMD320 may be configured to be implanted within a patient, such as patient 300 (fig. 3). The illustrative IMD 340 includes a housing 342, which housing 342 may be configured for transcatheter deployment. In some cases, this means that housing 342 has overall dimensions that enable IMD 340 to fit within a catheter or similar device to deliver IMD 340 via a vascular pathway. In some cases, the housing 342 may have an overall length that may be about 5 centimeters or less, or may be about 3 centimeters or less, and/or an overall width that may be about 2 centimeters or less, or may be about 1 centimeter or less. In some cases, for example, housing 342 may also be substantially transparent to EM energy (such as radiated EM energy along at least a portion of its length). For example, in some cases, first portion 342a of housing 342 may be substantially transparent to radiant EM energy, while second portion 342b of housing 342 may be less transparent to radiant EM energy. In some cases, second portion 342b of housing 342 may also be substantially transparent to radiant EM energy. In some cases, at least the first portion 342a of the housing 342 may be ceramic or glass. In some cases, the housing 342 (or portions thereof) may be a ceramic housing, a glass housing, or a polymer housing.

While the illustrative IMD320 (fig. 5) includes a single circuit 310, which may be single-function or multi-function, in some cases, IMD 340 (fig. 6) includes charging circuitry 344 and therapy circuitry 346. In some cases, the charging circuit 344 and the therapy circuit 346 may be located on different circuit boards or appear within different Integrated Circuits (ICs). In some cases, the charging circuit 344 and the therapy circuit 346, although shown as distinct elements, may be combined within a single IC or on a single circuit board. The charging circuit 344 may be operably coupled with the receive antenna 308 and the rechargeable battery 312, and may be configured to charge the rechargeable battery 312 using the radiated EM energy received by the receive antenna 308.

In some cases, IMD 340 may include a secondary battery 348 disposed within housing 342 and operatively coupled to therapy circuitry 346. In some cases, the secondary battery 348 may serve as a backup battery for the rechargeable battery 312. In some cases, secondary battery 348 may also be a rechargeable battery, and thus may also be operably coupled with charging circuit 344. In some cases, secondary battery 348 may be a non-rechargeable battery.

In some cases, the therapy circuit 346 can be operatively coupled to the first electrode 324 and the second electrode 326. Although two electrodes are shown, it is understood that IMD 340 may include three, four, or more different electrodes in some cases. In some cases, the therapy circuit 346 may be configured to sense one or more signals via the electrodes 324, 326 (or additional electrodes) and/or stimulate tissue via the

electrodes

324, 326. In some cases, therapy circuitry 346 may pace or stimulate tissue at least partially in response to one or more sensed signals. In some cases, first electrode 324 and second electrode 326 may be used in combination to communicate with other implanted devices and/or with external devices. In some cases, communication with other implanted devices may include conducted communication, but this is not required in all cases.

Figure 7 is a schematic cross-sectional side view of an illustrative LCP 400 having a rechargeable battery. Illustrative LCP 400 has a housing 402, the housing 402 being formed of a ceramic material, a glass material, or possibly a polymeric material. Accordingly, it should be appreciated that housing 402 is at least substantially transparent to radiant EM energy incident on LCP 400. The housing 402 defines an interior volume 404 that houses various components including, but not limited to, circuitry 406 and a rechargeable battery 408. In some cases, the circuitry 406 may be limited to recharging the rechargeable battery 408. In some cases, circuitry 406 may also have additional functionality such as sensing and/or pacing, but in some cases LCP 400 may include additional circuitry for additional functionality. In some cases, the circuit 406 is operably coupled with the first electrode 420 and one or more other electrodes (not shown).

Receive antenna 410 is operably coupled to circuitry 406. In some cases, as shown, the housing 402 itself may form at least one or more layers of the receive antenna 410. In some cases, the receive antenna 410 includes an outer metal layer 412 and an inner metal layer 414 connected by a through hole 416 extending through a hole 418 in the wall of the housing 402. Although outer metal layer 412 and inner metal layer 414 are schematically illustrated as simple layers, it should be understood that in some cases, outer metal layer 412 and/or inner metal layer 414 may include a pattern within the metal. Outer metal layer 412 and/or inner metal layer 414 may be formed, for example, by etching away portions of the base metal layer. In some cases, the outer metal layer 412 and/or the inner metal layer 414 may be formed via a deposition process. In some cases, the ceramic or other material forming housing 402 may be used as a dielectric layer between outer metal layer 412 and inner metal layer 414.

In some cases, the biocompatible polymer layer 422 may cover the outer metal layer 412. The biocompatible polymer layer 422 may be formed of, for example, polyimide or parylene. In some cases, depending on the exact material used to form housing 402 and whether the exact material is biocompatible, a polymer coating (not shown) may cover substantially all of the outer surface of housing 402 in order to improve biocompatibility. In some cases, particularly if the housing 402 is formed of a material having any porosity, the polymeric cover may help reduce the porosity.

In some cases, and as shown in fig. 7, receive antenna 410 may be built directly into housing 402 of LCP 400. However, in some cases, the receive antenna may be formed in or on a first structure that may then be inserted into or advanced over the device housing. For example,

fig. 8 shows a sleeve insert that may be inserted into a device housing, and fig. 9 shows an outer sleeve that may be provided on the device housing.

More specifically, fig. 8 illustrates a sleeve insert 500 configured to be insertable into a device housing 502. The device housing 502 includes an elongated cavity 504, the elongated cavity 504 configured to receive the sleeve insert 500 therein. While the elongated cavity 504 is shown as generally being the entire interior space of the device housing 502, it should be understood that in some cases the interior of the device housing 502 may be divided into compartments and the elongated cavity 504 may be one of those compartments. Sleeve insert 500 may be considered to have an outer surface 506 and an inner surface 508. The receiving antenna 510 may be built into the sleeve insert 500. In some cases, receive antenna 510 includes a first metal pattern 512 formed on outer surface 506 and a second metal pattern 514 formed on inner surface 508. The material forming sleeve insert 500 may, for example, comprise a dielectric layer, and may itself form a portion of receive antenna 510. In some cases, first metal mold 512 and second metal layer 514 may form an antenna with a resonator. Device housing 502 may be at least substantially transparent to radiated EM energy to allow the radiated EM energy to reach receive antenna 510.

Fig. 9 shows an outer sleeve 516 configured to fit over a device housing 518. In some cases, the outer sleeve 516 may be considered to have an outer surface 520 and an inner surface 522. The outer sleeve 516 may include a receive antenna 524 embedded within the outer sleeve 516. In some cases, for example, receive antenna 524 may include a first metal pattern 526 formed on outer surface 520 and a second metal pattern 528 formed on inner surface 522. The material forming the outer sleeve 516 may, for example, comprise a dielectric layer, and may itself form part of the receive antenna 524. In some cases, first metal mold 526 and second metal layer 528 may form an antenna with a resonator. In this embodiment, device housing 518 need not be substantially transparent to radiated EM energy, as radiated EM energy need not pass through device housing 518 to receive antenna 524.

Fig. 10 to 12 provide illustrative but non-limiting examples of receive antenna models. It should be understood that these models (and others) may be built directly into the device housing, as shown, for example, in LCP 400 of fig. 7. In some cases, these models (and other models) may be used to build a sleeve insert, such as sleeve insert 500 (fig. 8). In some cases, these models (and other models) may be used to construct an outer sleeve, such as outer sleeve 516. Fig. 10-12 show a cylindrical shape 600, which may for example represent a sleeve insert or an outer sleeve, or possibly a device housing. Although shown as a cylinder, it should be understood that the cylinder 600 may take any desired shape, size, or configuration.

The cylinder 600 includes an outer surface 602. In fig. 10, a first receive antenna 604 and a second receive antenna 606 are shown disposed relative to the outer surface 602. Receive

antennas

604 and 606 may be formed entirely on outer surface 602, for example. In some cases, receive

antennas

604 and 606 may be formed with components on outer surface 602 and components inside cylindrical form 600 (e.g., antennas with resonators).

Although two receive

antennas

604 and 606 are shown, the device may include any number of receive antennas. For example, fig. 11 is a schematic cross-sectional view showing a total of four receive

antennas

608, 610, 612, 614, each configured with a

first metal form

616, 618, 620, 622 disposed on the outer surface 602, and a corresponding

second metal form

624, 626, 628, 630 disposed on the inner surface 632, with

vias

634, 636, 638, 640 extending between the

first metal form

616, 618, 620, 622 and the

second metal form

624, 626, 628, 630.

Fig. 12 shows a receive antenna 642 that is arranged in a spiral or spiral pattern relative to the outer surface 602. The receive antenna 642 may, for example, be formed entirely on the outer surface 602. In some cases, the receive antenna 524 may be formed with components on the outer surface 602 and components inside the cylinder 600. Although indicated as a single helical receive antenna 642, in some cases, receive antenna 642 may alternatively have different segments, such as segment 642a, segment 642b, and segment 642 c.

It should be understood that in some cases, an antenna, such as a receive antenna, may have nulls, such as spatial nulls and/or frequency nulls. Spatial nulls indicate the direction from which no signal or very little signal can be received. A frequency null indicates a particular frequency or range of frequencies for which no signal or very little signal may be received. In some cases, if a device, such as an implantable device, includes two or more receive antennas, it will be appreciated that each antenna may have a spatial null. It may be advantageous to arrange two or more receive antennas such that the spatial nulls are not aligned in space. This may be particularly useful in implantable devices where the exact implant orientation of the device is uncertain and/or may change over time. In many cases, the device is constantly moving, especially if the implantable device is implanted in or on the heart. Fig. 13 and 14 provide several illustrative, but non-limiting examples of how antennas may be arranged so as to intentionally miss alignment with their respective spatial nulls.

In fig. 13, first receive antenna 650 is disposed relative to outer surface 602 of cylindrical shape 600 at a first angular orientation relative to longitudinal axis 648. Second receive antenna 652 is disposed relative to outer surface 602 at a second angular orientation relative to longitudinal axis 648, wherein the first angle is different than the second angle. In fig. 14, the first receive antenna 654 is disposed relative to the outer surface 602, oriented substantially perpendicular to the longitudinal axis 648. The second receiver antenna 656 is disposed relative to the outer surface 602, oriented substantially parallel to the longitudinal axis 648. It should be understood that one or more of receive

antennas

650, 652, 654, 656 may be formed entirely on outer surface 602, for example. In some cases, one or more of receive

antennas

650, 652, 654, 656 may be formed with components on outer surface 602 and components inside cylindrical form 600. It should also be understood that the angles shown in fig. 13 and 14 are merely illustrative.

It should be understood that this disclosure is, in many respects, only illustrative. Changes may be made in details, particularly in matters of shape, size, and arrangement of steps without exceeding the scope of the disclosure. To the extent appropriate, this may include using any feature of one exemplary embodiment that is used in other embodiments.

Claims

1. An Implantable Medical Device (IMD) configured to be implanted within a patient, the IMD comprising:

a housing configured for transcatheter deployment;

a plurality of electrodes exposed to an outside of the case;

a therapy circuit disposed within the housing, the therapy circuit being operably coupled to the plurality of electrodes and configured to sense one or more signals via one or more of the plurality of electrodes and/or stimulate tissue via one or more of the plurality of electrodes;

a rechargeable power source disposed within the housing and configured to power the therapy circuitry;

a receive antenna disposed relative to the housing and configured to receive radiated Electromagnetic (EM) energy transmitted through a patient's body, which is transmitted at a frequency between about 400MHz and about 3GHz, the receive antenna comprising a first metal pattern disposed on an inner curved surface of an elongated annular dielectric sleeve and a second metal pattern disposed on an outer curved surface of the elongated annular dielectric sleeve, wherein the elongated annular dielectric sleeve is coaxially aligned with and extends longitudinally along the housing, is shaped to conform to at least a portion of at least one of the therapy circuitry and the rechargeable power source along a wall of the housing, and wherein the first metal pattern, the second metal pattern, and the elongated annular dielectric sleeve together form the receive antenna; and

a charging circuit operably coupled with the receive antenna and the rechargeable power source, the charging circuit configured to charge the rechargeable power source using the radiated EM energy received via the receive antenna.

2. The IMD of claim 1, further comprising a secondary battery disposed within the housing and operatively coupled to the therapy circuitry, the secondary battery serving as a backup battery for the rechargeable power source.

3. The IMD of claim 2, wherein the secondary battery is a non-rechargeable battery.

4. The IMD of any of claims 1-3, wherein the housing is substantially transparent to radiant EM energy, and optionally comprises a ceramic, glass, or polymer housing.

5. The IMD of claim 4, wherein the receive antenna comprises a first metal pattern formed on an outer surface of a sleeve insert and a second metal pattern formed on an inner surface of the sleeve insert, and the sleeve insert is configured to be inserted into an elongated cavity of the housing of the IMD.

6. The IMD of claim 1, wherein the outer sleeve is configured to fit over and be fixed relative to the housing of the IMD.

7. The IMD of any of claims 1-6, wherein at least one of the plurality of electrodes forms part of the receive antenna.

8. An Implantable Medical Device (IMD) configured to be implanted within a patient, the IMD comprising:

a housing substantially transparent to radiated Electromagnetic (EM) energy along at least a portion of its length;

an electrical circuit disposed within the housing;

a plurality of electrodes exposed outside the housing and operatively connected to the electrical circuit;

a rechargeable power source disposed within the housing and configured to power the IMD including the circuitry;

a receive antenna disposed within the housing and configured to receive radiated EM energy transmitted through at least a portion of the housing that is substantially transparent to the radiated EM energy, which transmits at a frequency between about 400MHz and about 3GHz, the receive antenna comprising a first metal pattern disposed on an inner curved surface of an elongated annular dielectric sleeve and a second metal pattern disposed on an outer curved surface of the elongated annular dielectric sleeve, wherein the elongated annular dielectric sleeve is coaxially aligned with and extends longitudinally along the housing, is shaped to conform to at least a portion along a wall of the housing, and surrounds at least one of the electrical circuit and the rechargeable power source, and wherein the first metal pattern, the second metal pattern and the elongated annular dielectric sleeve together form the receive antenna; and is

The circuit is operably coupled with the receive antenna and the rechargeable power source, the circuit configured to charge the rechargeable power source using the radiated EM energy received via the receive antenna.

9. The IMD of claim 8, wherein the IMD comprises a Leadless Cardiac Pacemaker (LCP), an implantable monitoring device, or an implantable sensor.

10. The IMD of any of claims 8 or 9, wherein the receive antenna comprises a first receive antenna having a first null and a second receive antenna having a second null, the second null offset from the first null.

11. The IMD of any of claims 8-10, wherein the housing comprises ceramic or glass.

12. The IMD of any of claims 8-11, wherein the receive antenna is configured to receive sufficient radiated EM energy from a band of radiated EM energy transmitted from outside the patient to recharge the rechargeable power source at a faster rate than the rechargeable power source would deplete the IMD from powering up the IMD when the band of radiated EM energy is transmitted at an intensity that does not cause thermal damage to the patient.

13. The IMD of any of claims 8-12, wherein at least a portion of the housing has a substantially cylindrical profile, and the receive antenna comprises a planar antenna conforming to the substantially cylindrical profile.

14. An Implantable Medical Device (IMD) configured to be implanted within a patient, the IMD comprising:

a housing forming at least a portion of a receive antenna, wherein the receive antenna is configured to receive transmitted radiated Electromagnetic (EM) energy through a patient's body;

a plurality of electrodes exposed to an outside of the case;

a circuit disposed within the housing, the circuit being operably coupled to the plurality of electrodes and configured to sense one or more signals via one or more of the plurality of electrodes and/or stimulate tissue via one or more of the plurality of electrodes;

a rechargeable power source disposed within the housing and configured to power the circuitry; and

a charging circuit operably coupled with the receive antenna and the rechargeable power source, the charging circuit configured to charge the rechargeable power source using the radiated EM energy received via the receive antenna,

wherein the radiated Electromagnetic (EM) energy is transmitted at a frequency between about 400MHz and about 3GHz, the receive antenna comprising a first metal pattern disposed on an inner curved surface of an elongated annular dielectric sleeve and a second metal pattern disposed on an outer curved surface of the elongated annular dielectric sleeve, wherein the elongated annular dielectric sleeve is coaxially aligned with and extends longitudinally along the housing, is shaped to conform to at least a portion of at least one of the electrical circuit and the rechargeable power source along a wall of the housing, and wherein the first metal pattern, the second metal pattern, and the elongated annular dielectric sleeve together form the receive antenna.

15. The IMD of claim 14, wherein the housing forms one or more layers of the receive antenna.